MTU 12V & 16V 4000 Gx0/Gx1 Diesel Engine Shop Manual (2002–2007) (P/N MR20108/01E)

This MTU factory shop manual (P/N MR20108/01E) covers Series 4000 diesel engines in the 12V 4000 Gx0/Gx1 and 16V 4000 Gx0/Gx1 configurations.

PDF Search, Drawings, and Page Count

Text search and diagram detail: The manual has searchable text and no embedded PDF bookmarks. The starter schematic and wiring harness views are legible, with zoom helpful for the smaller terminal, connector, and injector labels.

The download is one printable English PDF. Its 533 pages include the cover, two amendment-service pages, and 65 pages that are blank or contain only page furniture such as headers and footers.

Engine Overhaul, Common Rail, and MDEC

This selection of workshop topics highlights the main overhaul and component procedures. The manual also covers crankcase ventilation and engine mount service.

• Overhaul schedules: Pre-overhaul condition checks, engine removal, disassembly and assembly schedules, test-stand run-in, acceptance testing, and return to operation.
• Internal engine repair: Crankcase and cylinder liner work, free-end gear train service, crankshaft and piston inspection, connecting rod checks, and driving-end and free-end PTO procedures.
• Cylinder heads and valve gear: Step-by-step instructions for cylinder head removal and installation, camshaft positioning, and valve drive adjustment.
• Fuel and air systems: High-pressure pump and injector replacement, accumulator and fuel line inspection, common rail leak testing, low-pressure fuel service, and turbocharger and intercooler replacement.
• Lubrication and cooling: Oil pump replacement, oil pressure valve checks, filter and heat exchanger service, coolant pump replacement, coolant chamber pressure testing, and thermostat inspection.
• Electrical and MDEC: Starter and alternator connections, W2 and W3 harnesses, separate W4 layouts for 12V and 16V engines, sensor and actuator service, and ECU 4 replacement checks.

MTU wrote this manual for trained service technicians with suitable workshop and test equipment and approved special tools.

From Condition Check to Acceptance Test

The pre-overhaul schedule uses a loaded test run to compare speed, temperatures, pressures, and fault indications with the engine’s own acceptance test record. It also calls for leak and exhaust-color checks, oil and coolant sampling, and an endoscopic examination. The comparison gives technicians a baseline for deciding which findings to investigate during overhaul.

MTU describes the scope as scheduled W6 service and unscheduled work on individual assemblies. The W5 checklist directs technicians to the maintenance schedule applicable to their engine. The test-stand run-in and acceptance checks also refer to the engine-specific acceptance test record for settings and comparison data.

Mechanical Inspection and Special Tools

Component sections pair overview drawings with tool lists, tightening specifications, settings, and inspection criteria. They cover threaded-bore and camshaft-bearing repair, carbon scraper ring inspection, crankshaft concentricity and bearing-shell checks, and connecting rod bore parallelism and twist. The tool lists identify hydraulic sets for main-bearing fasteners, bearing-shell tools, lifting fixtures, and camshaft timing equipment. The free-end PTO section flags a removal-order error that can destroy the radial lip seal.

Fuel, Cooling, and Electrical References

The high-pressure fuel section covers magnetic crack testing of the accumulator and line cleanliness after a ceramic pump bearing failure. It also identifies the limiting and pressure-relief valves and refers their checks to separate manufacturer documentation. The cooling chapters distinguish the high- and low-temperature circuits and show their measuring points.

Drawings include the crankcase exploded view, crankshaft assembly view, high-pressure injection line section, engine coolant schematic, starter circuit diagram, and engine harness layouts. The MDEC section explains how ECU 4 reports open circuits, shorts, and implausible sensor values. It also shows where to check harness routing and clamp positions to prevent chafing or heat damage.

REMAN Assemblies and Companion References

The manual covers removal and installation for the cylinder head, high-pressure pump, injector, coolant pump, MDEC, turbocharger, intercooler, vibration damper, starter, alternator, and fuel delivery pump. Internal overhaul of these REMAN assemblies is outside its scope. Transferring the ECU’s MEM data modules requires the separate Electronics Documentation.

MTU also lists separate parts catalogs for the 12V (M031 390) and 16V (M031 385), Operating Instructions M015 403, Tools Catalog M004 029, Fluids and Lubricants Specification A001 061, and Tolerance and Wear Limits List M070 040. Engine lifting, high-pressure fuel work, and hot coolant pressure tests require trained personnel and the precautions specified by MTU.

Oil and Coolant Pressure Test Examples

The lube oil pump section specifies a 15 bar opening pressure for the pressure-relief valve, checked with SAE 30 engine oil at 90–100 °C.

The post-assembly coolant chamber leak test specifies 5 bar for one hour with water at 80 °C.